The present Visayan Archipelago which shaped during the Neogene is interpreted as a mosaic of terranes which forms part of the convergence zone between the Philippine Sea Plate in the east and the Eurasian Plate in the west. On the Visayan islands and in the interjacent offshore areas, thick, mostly marine Cainozoic sediments have been deposited upon a Cretaceous "basement". Exact age determinations were carried out on a large number of samples from the Middle Oligocene to Pleistocene rock formations, thus allowing a biostratigraphic correlation with modern zonation schemes.

The sedimentary sequence locally contains good potential petroleum source rocks. The older formations, particularly the Upper Cretaceous of Cebu and the Upper Oligocene/ Lower Miocene of Leyte, have reached the thermal maturity required for the generation of liquid hydrocarbons. More than 200 wells have been drilled in the Visayan Basin since 1986. Although no commercial oil or gas fields have been found to date, the future hydrocarbon prospects are rated as favourable.